This invention relates to arrowheads having a recessed collar or body that is slidably positionable about a stem portion thereof.
Arrows have long been used for war, hunting and competitive sports. A conventional arrow has a shaft, a nock at one end that receives the bow string, an arrowhead or point that attaches to the opposite end, and fletchings. The fletchings are glued to the shaft near the nock end, and help to stabilize the arrow in flight, as it rotates. Arrowheads generally have a pointed forward end, and an opposite threaded shaft end that attaches the arrowhead to the arrow shaft. Arrowheads are also attached to the forward end of arrow shafts by glueing and other methods.
Arrowheads come in a variety of different sizes and configurations depending on their intended use. For example, there are specifically designed arrowheads for competitive target shooting, shooting fish, hunting birds or small game animals, and for hunting big game animals.
The most common type of arrowhead used in hunting is the fixed-blade arrowhead, which has a pointed tip end used for penetrating, and blades that each have a razor sharp edge for cutting. Most conventional fixed-blade arrowheads have replaceable blades which are held in a fixed position on the arrowhead. The replaceable blades attach to the arrowhead body in longitudinal grooves called blade slots. The tip of the arrowhead may be separably attachable to the arrowhead body or may be integral with it. Arrowheads for hunting are generally known as broadheads.
Arrowheads used for hunting kill the game animal by cutting vital organs such as the lungs and vascular vessels such as arteries, which causes rapid hemorrhaging and/or suffocation. Quick and humane kills are dependent on accurate shot placement, and upon the amount or volume of the animal tissue that is cut. Hunting arrowheads that cut more tissue are more lethal, and therefore are better. The volume of tissue that is cut is determined by the cutting diameter of the arrowhead, the number of blades it contains, and by the distance the arrowhead penetrates into the animal. The cutting diameter of an arrowhead is determined by how far each cutting blade extends outward from the arrowhead body. The further the blades extend outward the larger the cutting diameter is, and therefore the more cutting potential the arrowhead has.
A problem with conventional fixed-blade arrowheads is that having the desirable, large cutting diameters generally cause unstable arrow flight or poor arrow aerodynamics, which affects accurate shot placement. This can lead to non-lethal wounding of the game animal or missing the animal altogether. Unstable arrow flight in hunting arrows is generally caused by arrowhead aligning and centering problems. Arrowhead aligning and centering problems are prevalent when the arrowhead is attached to the arrow shaft such that the longitudinal axis of the arrowhead is not in line with the longitudinal axis of the arrow shaft. Alignment and centering problems in arrowheads are generally created by low tolerances or sloppiness in the manufacturing of the arrowhead body. When a mis-aligned arrowhead is attached to an arrow and the arrow is shot, as the arrow spins or rotates in flight non-stabilizing forces are induced on the front end of the arrow and cause inconsistent or erratic flight, which steers the arrow from its intended path. Since the cutting blades of fixed-blade arrowheads extend out from the arrowhead body when the arrowhead is in flight, the blades greatly magnify any non-stabilizing forces induced on the arrow from misalignment, and therefore increase erratic arrow flight. This is the main reason why conventional fixed-blade arrowheads are limited in the maximum cutting diameter they can have, while retaining sufficiently stable aerodynamics.
To create a hunting arrowhead that has both a maximum cutting diameter and stable aerodynamics, despite moderate manufacturing tolerances, blade-opening arrowheads were designed. Blade-opening arrowheads differ from conventional fixed-blade arrowheads in that the cutting blades are folded up or held adjacent to the arrowhead body in a retracted position while the arrow is in flight, but at impact with the game animal rotate or pivot into an open position, therefore exposing the sharp blade edges and cutting the animal. Since the blades of blade-opening arrowheads are held adjacent to the arrowhead body and do not extend very far out from it, any aligning or centering problems of a blade-opening arrowhead attached to an arrow will not noticeably steer the arrow or undesirably affect its flight trajectory. In this manner blade-opening arrowheads can have both a desirable large cutting diameter, and the stable arrow flight characteristics necessary for accurate shot placement. Blade-opening arrowheads can therefore potentially be more lethal.
Blade-opening arrowheads like conventional fixed blade arrowheads generally have an elongated arrowhead body, a tip end, and a threaded opposite end. The blades of blade-opening arrowheads have an attachment end which attaches the blades to the arrowhead body by a pivot pin, so that the blades can pivot or rotate between the retracted position and the open position. Blade-opening arrowheads also come in a variety of different types and styles. The blades of the most common type of blade-opening arrowheads, when in the retracted position have a leading blade end positioned near the tip of the arrowhead that protrudes outward from the arrowhead body, and is some times shaped like a wing. The leading blade ends of the most common type of blade-opening arrowheads, rotate away from the arrowhead body in a rearward direction when penetrating an animal. Particularly, the leading blade ends catch on the animal""s surface and serve to lever or rotate the blades into the open position. The blades of blade-opening arrowheads are also received in blade slots, which are machined or formed into the side of the arrowhead body.
Blade-opening arrowheads for hunting big game must be non-barbing, wherein the blades when in the open position must not inhibit or prevent arrow extraction from a game animal by barbing into the animal tissue. This makes it so non-fatally wounded animals can easily pull out an arrow still lodged in them. For an arrowhead to be non-barbing, the pivotal blades must rotate from the open position to an angle greater than ninety degrees, as measured between the rear edge of each blade and a location on the arrow shaft rearward of the blades.
Blade-opening arrowheads generally do not penetrate as deep as conventional fixed-blade arrowheads. Sometimes in hunting situations an arrow will not completely pass through the game animal and will not have sufficiently cut any vital organs or vascular vessels, and thus not having inflicted a lethal wound. Sometimes in these instances the arrowhead will have penetrated within the game animal near an artery or vital organ such that as the animal retreats, the arrowhead continues to cut as it moves within the animal, and the artery or vital organ is severed, and the animal is harvested. Conventional blade-opening arrowheads are generally not as lethal in these types of situations, as arrowheads having the cutting blades positioned near the tip of the arrowhead, such as conventional fixed-blade arrowheads. This is because the cutting blades of the most popular types of conventional blade-opening arrowheads when in the open position, are positioned approximately one and a half inches back from the arrowhead tip, and therefore cut a lesser volume of tissue despite equal arrowhead penetration depth.
To hold the blades of blade-opening arrowheads in the retracted position during flight until the arrowhead penetrates the animal, annular retention members such as O-rings are most commonly used. Other commonly known annular retention members are, rubber bands, tight fitting plastic sleeves, tape, heat-shrinkable fitting plastic sleeves, and other wrap materials. When the O-rings are stretched around the outside of the blades they exert a resistive force against the blades and hold the blades selectively in the retracted position.
O-ring use for blade retention is less than ideal. The elastomeric polymer materials are susceptible to drying-out and therefore cracking, which can lead to breaking of the O-ring during arrow acceleration when the arrow is shot. This will cause premature blade-opening and produce extremely erratic arrow flight and possible non-lethal wounding of the game animal. This may also cause severe lacerations to the archer. Also, bows shooting arrows at very high speeds can require as many as three O-rings to prevent premature blade-opening. The experience of learning this can be very undesirable for the archer. O-rings are a consumable item designed for one shot use, and the cost of constantly replacing them is a detrimental factor. Also, they are not user-friendly and are a general bother to worry about while out in the field.
Aside from consumer use considerations, humaneness to the hunted game animal is an important consideration as well. When the arrowhead penetrates the animal and the blades begin to rotate open, the more the O-ring is stretched the more resistive force it exerts back against the blades, thus impeding the rate of blade-opening. This can possibly prevent full blade-opening and a quick and humane kill. Also, extreme weather temperatures greatly affect the elasticity of O-rings; cold weather decreases elasticity which increases the likelihood of the blades not opening, and hot weather increases elasticity which increases the likelihood of premature blade opening.
Attempts in the prior art have been made to remedy the problems associated with O-ring use for blade retention of blade-opening arrowheads, but these attempts have their own problems as well. For example, the use of magnetism for blade retention is known to the art. The disadvantages of using magnets for blade retention are that magnets are heavy, relatively expensive, and can demagnetize. The use of a leaf spring for blade retention is also known to the art, where the leaf spring is positioned and held in the blade slot by a set-screw, which is usually also the pivot pin. One disadvantage of using a leaf spring for blade retention is the difficulty involved when replacing the blades; having to simultaneously line up a hole in the leaf spring, a hole in the blade, and a hole in the arrowhead body while inserting a set screw through all three members, for each blade. Another disadvantage of using a leaf spring for blade retention is limitations of the leaf spring, where a very small amount of dirt, debris or ice can prevent the leaf spring from deflecting, and also, the flexibility life span of the leaf spring can be short. This could possibly inhibit blade-opening altogether. Disadvantages of other blade retention methods known to the art are, reduced penetration of the arrowhead, structural weakening of various arrowhead elements, in-operability, and manufactural unfeasibleness.
It is apparent that there are much needed improvements in blade-opening arrowheads, both in consideration of the archery consumer and the hunted game animal.
It is apparent that there is a need for a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner, by methods other than O-rings or similar consumable elements, that is user-friendly, manufacturally feasible, and structurally strong.
It is also apparent that there is a need for a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner, that is operable and is not suspectable to malfunctioning by contamination of dirt, debris, or ice and/or by short life span of the blade retention method.
It is yet further apparent that there is a need for a blade-opening arrowhead that is capable of driving the razor cutting edges of the blades from the open position, forwardly into uncut or unpenetrated tissue of an arrowed game animal when the arrow is lodged in the animal, especially when the animal has not been fatally or lethally hit, thus to increase the lethality of the arrowhead, and to be more humane to the animal.
It is one object of the present invention to provide blade-opening arrowheads with blade retention methods that do not require the use of consumable annular members such as O-rings.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted in-flight position, in a secure or locked manner by methods other than O-rings or similar elements, that is user-friendly, manufacturally simple, and structurally strong.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted in-flight position, in a secure or locked manner that is operable and is not suspectable to malfunctioning, especially by contamination of dirt, debris, ice and/or by short life span of the blade retention method.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner by releasably latching the blade edge of each blade to the arrowhead body or equivalent. Specifically where an urging force urges the blades in a forward direction to securely hold the edge of each blade engaged against the arrowhead body, and therefore the blades are securely held adjacent to the arrowhead body when in a retracted position but freely rotate into an open position when the arrowhead penetrates an object.
It is still another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner by releasably latching the blade edge of each blade to a holding element. Specifically where an urging force urges the holding element to securely hold the edge of each blade engaged against the holding element, and therefore the blades are securely held adjacent to the arrowhead body when in a retracted position but freely rotate into an open position when the arrowhead penetrates an object.
It is yet further another object of the present invention to provide a blade-opening arrowhead that is capable of driving or continually urging the razor cutting edge of each blade from the open position, forwardly into uncut or unpenetrated tissue of an arrowed game animal.
The foregoing objects and advantages and other objects and advantages of the present invention are accomplished with a hunting arrowhead that attaches to the forward end of an arrow shaft, where a plurality of blades are pivotally connected to an arrowhead body. The blades freely rotate from an in-flight retracted position to an open position when the arrowhead penetrates an object, or when acted upon by a sufficient opening force. When the blades are in the in-flight retracted position they are securely held selectively adjacent to the arrowhead body by engagement of a blade edge of each blade to a holding element.
Such a blade-opening arrowhead according to one preferred embodiment of this invention has an arrowhead body with a tip end used for initial penetration and an opposing threaded shaft end that screws or threads the arrowhead to an arrow. The tip end may be removably attached to the arrowhead body, and may be made of material different than the rest of the arrowhead body. The arrowhead body has a plurality of blade slots, one for each respective blade. Each blade has a first end, an opposing second end and an edge extending about its periphery. One blade edge of each blade is sharpened for cutting. The first blade ends or the leading ends each have a protruding wing that is exposed out from the arrowhead body when the blades are in the retracted position. The wings serve to increase the moment-arm for levering or rotating the blades to the open position. The second end of each blade has an aperture or hinge pin receiving hole for receiving a pivot pin or a hinge pin. The arrowhead body also has a hinge pin receiving hole for each blade. The arrowhead body hinge pin receiving holes are recessed or drilled into the two opposing sidewalls of each blade slot, and are threaded to receive the threaded hinge pins. A single hinge pin is used for each blade, and when the blades are positioned in the blade slots, each hinge pin is extended through the aperture of a corresponding blade and is screwed into the arrowhead body. This pivotally connects the blades to the arrowhead body. The cross-sectional area or open area of each blade aperture is greater than the cross-sectional area of its corresponding hinge pin, such that a gap is created between each hinge pin and blade aperture of each blade, when the hinge pins are extended through the blade apertures. These gaps allow each blade to freely move in a forward and rearward direction independent of the arrowhead body and corresponding hinge pin. The blade edge of the first end of each blade has a catch lip or a bump protruding out from it near the cutting edge. The arrowhead body has one receiving notch or holding element formed in it for each blade. The notches are situated near the top of each blade slot and are recessed into the arrowhead body. An annular recess encircling the arrowhead body is situated below the blade slots, and is recessed into the arrowhead body. This annular recess communicates with each blade slot and leaves or defines a stem shaped portion on the arrowhead body. An annular compression spring or coil spring is positioned in the annular recess, with a separate annular ring positioned forward or above the annular spring. Both the annular ring and annular spring are slidably positioned around the stem portion of the arrowhead body, such that the annular ring contacts the second end of each blade. An annular blade-stop washer shaped like a doughnut, also having a recessed portion shaped to contain the annular spring, is slidably positioned around the arrowhead body stem below the annular spring, and contacts the rear end of the annular spring. The blade-stop washer has a sloped outer and upper side, that serves to abut against the blades when they are rotated to the fully open position, thus defining the cutting diameter of the arrowhead when the blades are in the fully open position.
When a blade-opening arrowhead according to the preferred embodiment of this invention as described above, is tightly fastened to the forward end of an arrow shaft, the blade-stop washer is tightened-up against both the arrow shaft and the arrowhead body. This tightening causes the annular spring to be compressed between the blade-stop washer and the annular ring. This compression or biasing of the spring causes an urging force to be exerted against the second ends of the blades in a generally axial direction. The annular ring serves to transfer the urging force equally to all blades. Since a gap exists between each hinge pin and each blade aperture, the urging force moves the blades forward relative to the arrowhead body, and engages or receives the catch lips on the blades into their corresponding receiving notches in the arrowhead body. The continual compression of the annular spring provides a continual urging force which maintains the engagement of the catch lips and notches, thus releasably latching and securely holding the blades selectively in the retracted position. The urging force is strong enough to maintain the blades in the retracted position when the arrow is exposed to incidental forces, such as those produced from transporting the bow, nocking an arrow to the bow string, and acceleration when the arrow is shot. The urging force is weak enough however, to be easily overcome when the arrow impacts or begins to penetrate a game animal.
When the arrowhead according to the above described preferred embodiment initially penetrates an animal, the first ends or leading ends of the blades catch on the animal""s surface and the blades are driven rearwards which unlatches the blades. At initial penetration the annular spring is then compressed such that the catch lips are disengaged from the notches sufficiently that the blades lever-out and freely rotate towards the open position. With the blades in the open position, the urging force of the annular spring continually urges the cutting edges of each blade in a forward direction, providing the ability to further cut additional animal tissue, should the arrow still be lodged in the animal.
All that is required to securely lock the blades back in the retracted position, is to simply push each blade back into the retracted position, and the spring compresses as the catch lips are received back into the notches. Once the catch lips are received into the notches, the continual urging force of the spring simply maintains the blades in the retracted position again. Also, when the sharp edges of the blades become dull, all that is required to change the blades is to un-compress the spring by slightly unscrewing the arrowhead from the arrow shaft, and then remove the threaded hinge pin, insert a new blade, and re-insert the hinge pin. There is no requirement to spend additional time and effort lining up tiny holes in other tiny elements such as a leaf spring, with the blade aperture and arrowhead body pivot pin receiving hole, when changing blades or when replacing the spring element or elements.
Blade-opening arrowheads according to other preferred embodiments of this invention differ from the above described preferred embodiment in that they have an annular hinge pin, where the plurality of blades are all attached to the single annular hinge pin. The annular hinge pin is slidably positioned on the stem located near the rear end of the arrowhead body, and is received in the same annular recess as the annular spring and annular ring. According to one such annular hinge pin embodiment, there is substantially no gap between the hinge pin and each blade aperture, and the blades and hinge pin are both urged or moved forward together by the annular spring when the catch lips are received or engaged into the notches. In another annular hinge pin preferred embodiment according to this invention, a gap is formed between the hinge pin and each blade aperture, and the blades are urged or biased by the annular spring when the catch lips are received into the notches.
A blade-opening arrowhead according to another preferred embodiment of this invention, also has an annular recess encircling the arrowhead body, situated below the blade slots, which defines a stem shaped portion on the arrowhead body, and which houses an annular spring and an annular ring. The blade-opening arrowhead according to this preferred embodiment has a catch lip and an adjacent notch in the second end of each blade. Each notch is positioned medial to its corresponding catch lip when the blades are in the retracted position. Each notch is defined by its corresponding catch lip, wherein the notches were created by removal of blade material in fabricating the protruding catch lips. The annular spring urges the annular ring against each catch lip and into each notch, thus engaging the blade edges at the second end of each blade, and securely holding the blades selectively adjacent to the arrowhead body when in the retracted position. The blades are prevented from rotating outwards prematurely by the lateral or outside edge of each blade notch abutting against the lateral surface of the annular ring. When the blade-opening arrowhead according to this preferred embodiment impacts a game animal and the blades begin rotating outwards, the catch lips or lateral edges of the notches are driven into the annular ring, which compresses the annular spring such that the tip of each catch lip slips over the annular ring, thus disengaging the annular ring from the notches and thus allowing the blades to freely rotate towards the open position.
According to another preferred embodiment of this invention, an annular spring is positioned in an annular recess situated near the forward end of the arrowhead body within a separably attachable tip piece. The blade-opening arrowhead according to this preferred embodiment has a catch lip and an adjacent notch in the first end of each blade. Each notch is positioned lateral to its corresponding catch lip when the blades are in the retracted position. Also the notch and catch lip of each blade are situated near the cutting edges of the blades. Each notch is defined by its corresponding catch lip, wherein the notches were created by removal of blade material in fabricating the protruding catch lips. The annular spring urges the annular ring against each catch lip and into each notch in a rearward generally axial direction, thus latching the blade edges and securely holding the blades selectively adjacent to the arrowhead body in the retracted position. The blades are prevented from rotating outwards prematurely by the medial or inside edge of the blade notches abutting against the medial surface of the annular ring. When the arrowhead impacts an animal and the blades begin to rotate outwards, the catch lips are driven into the annular ring, which forces the annular spring to compress until the catch lips freely slip under the annular ring. In this manner the blades are unlatched and freely rotate towards the open position.
The blade-opening arrowheads according to this invention, use no consumable items such as O-rings, for blade retention. The blade retention methods of the blade-opening arrowheads according to this invention, are simple and user-friendly. The blade-opening arrowheads according to this invention provide blade retention methods that are not suspectable to malfunctioning when exposed to the harsh conditions commonly encountered in the field, and when subjected to prolonged use. Should ice, dirt or debris get intermingled with the annular spring of the type preferred for use according to this invention, the annular spring will still serve to produce an effective blade retention urging force, and to allow the timely opening of the blades at target impact. This is so because the spaces between the spring coil wires are large enough to handle a relatively large accumulation of foreign matter, yet have room to allow adequate spring compressing. Also, the length of spring flexibility life of the annular spring according to this invention, under normal use considerations, is indefinite. This is such because the diameter or gauge of the wire, and the general diameter of the spring are large enough that the annular spring is extremely rugged and durable in nature, especially when compared to the relatively light work load required of it.
The blade-opening arrowheads according to this invention are also more humane, and more lethal than prior art arrowheads. Should the arrow become lodged in the game animal, particularly when the animal has not been fatally hit, the blades will be driven or continually urged in a forward direction by the urging force of the annular spring, cutting additional tissue, which could possibly sever any nearby arteries or vital organs, and thus decrease the wounding loss. This trait of cutting additional tissue is a feature that no prior arrowhead performs. The blade-opening arrowheads, according to this invention are also structurally strong, simple and feasible to manufacture, and operable.
As has been shown in the above discussion, the blade-opening arrowheads according to this invention overcome deficiencies inherent in prior art arrowheads.